1. Field of the Invention
This invention relates to a power train system for a vehicle.
2. Description of the Prior Art
Recently it has been proposed to rigidly connect the power unit positioned in the front of the vehicle body to the differential positioned in the rear of the vehicle body by a power plant frame which has a substantially U-shaped cross-section and is flexurally stiff and torsionally flexible, thereby reducing the engine vibration and suppressing the windup vibration of the differential due to torque reactions from the rear wheels. See Canadian Patent No. 1158265, for instance.
However when the power unit and the differential are rigidly connected by the power plant frame, an impact acting in the longitudinal direction of the vehicle body upon collision or the like is directly transmitted to the differential or the power unit through the power plant frame and the impact cannot be sufficiently absorbed.